42,772 articles
Osmond Fisher
Osmond Fisher (1817–1914) was an English clergyman and geologist, rector of Harlton, who wrote the first geophysics textbook, The Physics of the Earth's Crust (1881), anticipating convection currents and continental mobility.
Osmosis
Osmosis, from the Greek for "push," is the net movement of water across a semipermeable membrane toward the higher solute concentration, quantified by van 't Hoff's law.
Osmotic concentration
Osmotic concentration, also called osmotic strength or osmolarity, is the concentration of osmotically active particles in a solution, expressed as osmoles per liter or per kilogram.
Osmotic pressure
Osmotic pressure, also known as osmotic potential, is the pressure needed to stop water flowing across a semipermeable membrane into a solution. It is a colligative property of solutions.
Osorno
Osorno (Volcán Osorno) is a 2,659-m glaciated stratovolcano in Chile's Los Lagos Region between Lakes Llanquihue and Todos los Santos; last confirmed eruption 1869, sixth on Chile's volcanic risk ranking, dominantly basaltic unlike nearby andesitic Calbuco.
Osprey optimization algorithm
The osprey optimization algorithm (OOA) is a population-based metaheuristic for continuous and engineering optimization, introduced by Mohammad Dehghani and Pavel Trojovský in 2023, modeling how ospreys hunt fish.
OSQP
OSQP (Operator Splitting Quadratic Program) is an open-source numerical optimization package, written in C, that solves convex quadratic programs using the alternating direction method of multipliers.
Ossian Aschan
Adolf Ossian Aschan (1860–1939) was a Finnish organic chemist and politician, professor of chemistry at the University of Helsinki from 1908 to 1927 and a member of Parliament in 1910–1911.
Ostap Stepanovich Parasyuk
Ostap Stepanovich Parasyuk (Остап Степанович Парасюк; 1921–2007) was a Ukrainian mathematician and theoretical physicist, co-author of the Bogoliubov–Parasyuk theorem subtracting ultraviolet divergences in quantum field theory.
Osterwalder–Schrader axioms
The Osterwalder–Schrader axioms are mathematical conditions on Euclidean Green's functions that determine a unique relativistic quantum field theory, established by Konrad Osterwalder and Robert Schrader in 1973.
Ostrowski's theorem
Ostrowski's theorem is a 1916 result in number theory stating that every nontrivial absolute value on the rational numbers is equivalent to the usual real one or a p-adic one.
Ostwald ripening
Ostwald ripening is the dissolution of small crystals or sol particles and redeposition on larger ones, a coarsening process first described by Wilhelm Ostwald in 1901.
Oswald Teichmüller
Oswald Teichmüller (1913–1943) was a German mathematician who founded Teichmüller theory, the study of Riemann surfaces through quasiconformal mappings, and was also a committed Nazi activist.
Oswald Veblen
Oswald Veblen (1880–1960) was an American mathematician who worked on geometry and topology and built the Princeton mathematics department and the Institute for Advanced Study.
Otakar Borůvka
Otakar Borůvka (1899–1995) was a Czech mathematician at Masaryk University in Brno who published the first solution of the minimum spanning tree problem in 1926.
Othniel Charles Marsh
Othniel Charles Marsh was an American vertebrate paleontologist, the first professor of the field at Yale, who named Apatosaurus, Stegosaurus, and Triceratops and waged the Bone Wars.
Otoacoustic emission
An otoacoustic emission (OAE), or Kemp echo, is a low-level sound produced by the cochlea and recorded in the ear canal, first recorded by David Kemp in 1978.
Ott-Heinrich Keller
Ott-Heinrich Keller (1906–1990) was a German mathematician who posed Keller's conjecture on tilings of space by cubes in 1930, and held the chair of mathematics at Halle-Wittenberg from 1951 to 1971.
Otto cycle
The Otto cycle is the air-standard thermodynamic cycle modeling spark-ignition engines, named after Nicolaus Otto, whose 1876 engine first ran successfully on the four-stroke cycle.
Otto Diels
Otto Paul Hermann Diels (1876–1954) was a German organic chemist at Kiel University who shared the 1950 Nobel Prize in Chemistry with Kurt Alder for the diene synthesis.
Otto E. Neugebauer
Otto E. Neugebauer (1899–1990) was an Austrian-born American historian of the exact sciences who created the modern study of ancient Egyptian and Babylonian mathematics and astronomy, winning the 1986 Balzan Prize.
Otto Fischer (German chemist)
Otto Fischer (Otto Philipp Fischer) was a German chemist who held the chemistry chair at the University of Erlangen from 1885 to 1925 and worked on organic dyestuffs.
Otto Folin
Otto Folin, full name Otto Knut Olof Folin, was a Swedish-born American biochemist at Harvard Medical School who pioneered quantitative clinical chemistry and the Folin–Wu blood analysis system.
Otto Forster
Otto Forster, born 1937 in Munich, is a German mathematician and emeritus professor at LMU Munich known for Riemann surfaces, algorithmic number theory, and his Analysis textbook series.
Otto Hahn
Otto Hahn was a German radiochemist who, with Fritz Strassmann, discovered nuclear fission in 1938, winning the 1944 Nobel Prize in Chemistry and later campaigning against nuclear weapons.
Otto Haxel
Otto Haxel (1909–1998) was a German nuclear physicist who co-discovered the nuclear shell model in 1949, led research at Heidelberg and Karlsruhe, and signed the 1957 Göttingen Declaration against nuclear weapons.
Otto Heckmann
Otto Heckmann (1901–1983) was a German astronomer who classified relativistic world models, led the Hamburg Observatory, and became the first Director General of the European Southern Observatory in 1962.
Otto Hölder
Otto Hölder was a German mathematician (1859–1937) who held the chair at Leipzig and gave his name to Hölder's inequality, Hölder spaces, and the Jordan–Hölder theorem.
Otto Hönigschmid
Otto Hönigschmid was an Austrian-born chemist, the last classical atomic-weight analyst, who determined the atomic weights of nearly fifty elements and gave the first chemical proof of isotopes.
Otto Kratky
Otto Kratky (1902–1995) was an Austrian physical chemist who made small-angle X-ray scattering a general method for determining the size and shape of macromolecules in solution, and designed the Kratky camera.